I have too many 200mm lenses (maybe one reason I am non-plussed by the new lenses announced by Olympus this week). My favorite right now is a Konica Hexanon 200mm f/4.0 that I bought from someone on this forum. I like the way it feels and focuses, and the images it captures. (I'll try to upload a couple of pix.)
I actually have even more 135 mm lenses

and my favorite of these is a Contax Sonnar f/2.8. As a result I've been eyeing this 200mm lens on eBay:
(link). He's had to relist it twice, each time at a lower price. I figure at this price it will go soon. The odd thing is that it has been modified (and chipped!) to work on a standard 4/3 camera. It is possible that it could communicate with the camera using an adapter.
Of course, the real fantasy lens is this one:
(link)
Even the photo he took of the lens is beautiful - lol.